Precautions for installation of power cables: keep 2m distance when the cable is installed in parallel with the thermal pipe, and 0.5m should be maintained when crossing. The cable shall be installed at a distance of 0.5m in parallel or across other pipelines. When the cable is directly buried and installed, the direct buried depth of 1-35kv cable is less than 0.7m. When 10KV and below cables are installed in parallel, the net distance between them shall not be less than 0.1m and 10-35kv shall not be less than 0.25m. The distance of cross installation is not less than 0.5m. Cable laying temperature lower than 0 ℃, bending radius: multi-core cable or 15 (D + D), a single cable 20 or more (D + D), (D for cable diameter, D) for the conductor diameter. ? 6KV and above cable connector:? When installing the terminal head of the cable, the semiconductor electrical shielding layer must be stripped off. During operation, the insulation shall not be damaged. The shield end should be flat and the graphite layer (carbon particles) should be clean. (2) plastic cable end copper tape screened and armor must be good grounding, the short circuit also follow this principle, avoid unbalanced three-phase run ShiGang armoured end produce inductive electromotive force, and even "lighter" and sheath and other accidents. It is required to use my tinplate to braid copper wire for grounding lead. When connecting with the cable copper belt, it should be welded with chromium-iron tin. ? The shield of three-phase copper tape should be connected with ground wire respectively. Note that the shielded ground wire and steel armor ground wire should be separately drawn out and insulated from each other. The position of the welded ground wire should be as low as possible. Basic requirements for cable terminals and intermediate joints: a. good conductor connection; B. The insulation is reliable, and it is recommended to use irradiated cross-linked heat-shrinkable silicone rubber insulation materials; C. good sealing; D. sufficient mechanical strength to meet various operating conditions. The end of the cable must be used to prevent water and other corrosive materials from corroding, in order to prevent the water tree caused by the aging of the insulation layer and breakdown. Crane or forklift should be used for the loading and unloading of cables. It is forbidden to run flat or lay flat. For installation of large cables, cable laying cart should be used to avoid external damage or abrasion caused by manual dragging. If the cable cannot be laid in time for some reason, it should be stored in a dry place to prevent sunlight from exploding and water entering the end of the cable. ? Note: the installation of wire and cable should be familiar with the performance of wire and cable installation personnel or full-time technical personnel, if there are still unclear matters, ball related technical department or technical department of our factory.
特种电缆就是有特殊用途、可以在特定场合使用的电缆，比如可以耐高温，耐酸碱，防白蚁，以及在轮船飞机核电站等场合使用的电线电缆。
就分类来说，它与电力、控制、计算机电缆等类别不属于同一种分类方法，也就是上列电缆中也包含有特种电缆在内。
一般特种电缆都需要制定企业内控标准。
特种电缆是一系列具有独特性能和特殊结构的产品，相对于量大面广的普通电线电缆而言，具有较高技术含量、较严格使用条件、批量较小、较高附加值的特点。
往往采用新材料、新结构、新工艺和新的设计计算。
IA-DJVP2V2R IA-DJYP2V2R IA-DJYJP2V2R 本安型、本安型、铜塑复合膜分对屏蔽、总屏蔽软结构 。
IA-DJVP3VP3R IA-DJYP3VP3R IA-DJYJP3VP3R 本安型、本安型、铝塑复合膜分对屏蔽、总屏蔽软结构。
Flame retardant performance: under specified test conditions, specimen was burning, after removed test of ignition, flame spread only in a limited range, residual flame or residual burning characteristics of self extinguishing reaction in the limited time.
Purpose and features: this product is suitable for transmission and communication in mine and underground monitoring. This product is flame retardant. Ii. Implementation: mt818.14-1999 fire retardant communication cable for coal mine and enterprise Q/ jg1710-2006. Iii. Usage features:? 1, cable long-term working temperature: - 30 ~ 60 ℃, cable laying temperature:????? Not below 0 ℃ 3, MHYV type bending radius is not less than 10 times of cable diameter. The bending radius of MHYBV is not less than 10 times of the cable diameter. The bending radius of MHYVP is not less than 10 times of cable diameter. The bending radius of MHY32 is not less than 15 times of the cable diameter.
一个很重要的需要注意的一点是，高的分辨率并不代表高的精度。
，两个同样精度的旋转编码器,一个分辨率是3600PPR,而一个是10000PPR。
低分辨率的编码器(3600PPR)可以提供0.1°的测量距离，而高分辨率的编码器可以提供一个更小的测量距离，二者的精度是相同的，高分辨率编码器仅仅是具有将0.1°缩小到更小的增量距离的能力。
编码器分辨率和精度是两个独立的概念，如上图所示，两个编码器具有相同的分辨率(24PPR)具有不同的精度。
形式导体标称直径mm。
聚氯乙烯绝缘矿用执行标准:YD/T。
产品用途:本产品适用于固定敷设在矿井、巷道等作通信干线及分线箱与机的连接线。
HUVV铜芯聚氯乙烯绝缘聚氯乙烯扩套矿用电缆敷设在矿井中，一般场合对绞式聚乙烯绝缘聚氯乙烯护套市内通信电缆型号名称CPEV-S绞式聚乙烯绝缘聚氯乙烯护套市内通信电缆。
航空航天、机车车辆、能源、钢铁、有色金属冶炼、石油开采、电机、建设等领域需用耐高温电线电缆。
长期连续工作温度125度、135度、150度、180度、200度、250度及250度以上的耐高温电线电缆，常用的有辐照交联聚烯烃、硅橡胶、氟树脂、聚酰亚胺、云母、氧化镁等电线电缆。
现介绍；两种新型耐高温电线电缆。
ZR-BPQYJVP3X4+3X0.75变频电缆
有强电与弱电之分，这里介绍一种强电用低感电缆。
此电缆带有热耗散装置，用于各类接触焊机、电弧焊机与气动焊钳间相连接的新型水冷式低感电缆，具有结构简单合理、冷却水流通量大、不会形成堵塞阻断和限流现象、散热效果好、使用寿命长等特点。
KVV22铜芯聚氯乙烯绝缘聚氯乙烯护套钢带铠装控制电缆。
KVVR铜芯聚氯乙烯绝缘聚氯乙烯护套控制软电缆。
KVVRP铜芯聚氯乙烯绝缘聚氯乙烯护套编织屏蔽控制软电缆。
KVVP-22铜芯聚氯乙烯绝缘聚氯乙烯护套铜丝编织屏蔽钢带铠装KVVP2-22铜芯聚氯乙烯绝缘聚氯乙烯护套铜带屏蔽钢带铠装。
使用特性：工作温度：—般型不超过70℃型号后带105的最高不超过105℃额定电压Uo/U：450／750V址低环境温度：固定敷设－40℃;非固定敷设－15℃最小弯曲半径：无铠装层电缆应不小于电缆外径的6倍带铠装层电缆应不小于电缆外径的12倍。
HB型混合式步进电机结构为两个导磁圆盘中间夹着一个永磁圆柱体轴向串在一起，两个导磁圆盘的外圆齿节距相同，与前述的VR型可变磁阻反应式步进电机转子结构相同，其两个圆盘的齿错开1/2齿距安装，转子圆柱永磁体轴向充磁一端为N极，另一端为S极。
此种电机转子与前面叙述的PM型永磁步进电机转子从结构来看，PM型转子N极与S极分布于转子外表面，要提高分辨率，就要提高极对数，通常20mm的直径，转子可配置24极，如再增加极数，会增大漏磁通，降低电磁转矩；而HB型转子N极与S极分布在两个不同的软磁圆盘上，可以增加转子极数，从而提高分辨率，20mm的直径可配置100个极，并且磁极磁化为轴向，N极与S极在装配后两极磁化，充磁简单。
这种新型低感电缆也包括电缆和电缆端头上固装着的接头，且电缆也是由正极缆芯和负极缆芯同装于外胶管中构成。
由于这类低感电缆一般都是用于电压为25-50V、电流在7000-12000A之间的场合，冷却水在电缆中的短路导电现象基本上可忽略不计，在此低感电缆中没有使用隔离正极缆芯和负极缆芯的橡胶软管，只是特别设置了一条横断面呈轮辐状（俗称“梅花芯”状）的芯架，其“轮心”和相邻“辐条”间所围成的空间在顺轴线方向上即形成纵向沟槽，芯架上的纵向沟槽与电缆所配置的正极缆芯的总根数相同，其电缆部分就是以正极缆芯和负极缆芯分别搁于芯架的纵向沟槽内装置在外胶管中构成。
正极缆芯和负极缆芯的两端头部分别同极集合成束夹固于缆芯夹中，固装在接头上，电缆的外胶管的端头部套装在接头的尾端部，并用套装在外胶管外的收紧箍紧密封。
严格来讲，编码器只会告诉你改如何定位，要如何执行，是需要靠数控系统（或者plc之类控制器）控制伺服或者步进电机来实现定位的，编码器好比人的眼睛，知道电机轴或者负载处于当前某个位置，工业上用的一般是光电类型编码器，下边简单说明一下。
简单说下编码原理和位置测量光电编码器是在一个很薄很轻的圆盘子上，通过紧密仪器来腐蚀雕刻了很多条细小的缝，相当于把一个360度，细分成很多等分，比如成1024组，这样每组之间的角度差是360/1024度=0.3515625度。
(如计量测试、信号显示、自测遥测、计算机联网、报警等)产品型号：KVV硬芯聚氯乙烯绝缘聚氯乙烯护套控制电缆应用标准：GB9330电缆结构：导体：单根粗铜丝或多根铜丝绝缘：PVC/A型聚氯乙烯绝缘填充物：PP带或无纺布包裹缓冲护套：ST1聚氯乙烯护套颜色：黑色(RAL9005)灰色(RAL7001)额。